So this is all a bunch of moral panic, and ablest bs for a number of reasons.
A: Extra time on tests really isn't the end of the world that people make it out to be. If someone needs a bit longer to do their work, what is the issue? The point of schooling is that people understand the subject matter, so if someone needs a bit more time to get it right, what's the issue? I'd rather my doctor take a day extra with my test results to really think about them than give me a knee jerk reaction.
B: I see a lot of people here who are really, really ill informed on disability which isn't surprising given that it's Slashdot, but right now we're in a time where autism and ADHD diagnoses are skyrocketing due to increased diagnostic clarity. The number of severely high needs individuals has stayed relatively static, but we're getting a lot better at screening for ADHD (there's literally an app that has an 80% success rate that can be used as a preliminary screener by any school nurse) especially in underrepresented populations. And given that a lot of the stigma around neurodivergence is going down (although it's starting to rise again) people are getting more comfortable disclosing that they have a learning disability, even if they've been able to be successful academically. It's kind of like identifying that you have asthma and need an inhaler and some accommodations to participate in PE- you can still participate and likely pass, but you will need some extra accommodation. But at the end of the day, providing accommodations like extra time on tests and other relatively benign things isn't the end of the world. The point of schooling is to show subject matter expertise, and someone can still show that if they have an extra hour to finish the test.
and C: ADHD absolutely does exist. My wife's working on her chem degree with ADHD, and it's brutal- she needs about three times as much time to study as her peers because her mind literally won't focus, and the only pill that actually does any good is damn near impossible to get. I get so tired of people who act as armchair psychologists because they read some article.